# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1779718307 -3600
# Node ID 25beb66fab3836138ecdf22dc1c6440416158c72
# Parent  af87d31dcae40ae38e5ae4adac8fd9e0d44ce5d4
util.crypto: Use post-Lua 5.1 buffer API

Tha Lua 5.1 buffer API was frustrating to work with. luaL_prepbuffer() only
allocates LUAL_BUFFERSIZE - there is no way to request a specific size.
LUAL_BUFFERSIZE is set to BUFSIZ by default, which is generally 8192 bytes on
Linux, however it may vary between platforms.

The variation means this buffer could potentially overflow (small BUFSIZ with
large signature).

The Lua 5.2+ buffer API enables requesting a specific buffer size, so that's
what we do now.

diff -r af87d31dcae4 -r 25beb66fab38 util-src/crypto.c
--- a/util-src/crypto.c	Mon May 25 14:51:15 2026 +0100
+++ b/util-src/crypto.c	Mon May 25 15:11:47 2026 +0100
@@ -150,16 +150,13 @@
 		return 1;
 	}
 
-	// COMPAT w/ Lua 5.1
-	luaL_buffinit(L, &sigbuf);
-	sig = memset(luaL_prepbuffer(&sigbuf), 0, sig_len);
+	sig = (unsigned char *)luaL_buffinitsize(L, &sigbuf, sig_len);
 
 	if(EVP_DigestSign(md_ctx, sig, &sig_len, msg, msg_len) != 1) {
 		lua_pushnil(L);
 	}
 	else {
-		luaL_addsize(&sigbuf, sig_len);
-		luaL_pushresult(&sigbuf);
+		luaL_pushresultsize(&sigbuf, sig_len);
 		return 1;
 	}